• Title/Summary/Keyword: Dual problem

Search Result 713, Processing Time 0.027 seconds

A New Understanding on Environmental Problems in China - Dilemma between Economic Development and Environmental Protection - (중국 환경문제에 대한 재인식 -경제발전과 환경보호의 딜레마-)

  • Won, Dong-Wook
    • Journal of Environmental Policy
    • /
    • v.5 no.1
    • /
    • pp.45-70
    • /
    • 2006
  • China has achieved great economic growth above 9% annual since it changed to more of a market economy system by its reform and open-door policy. At the same time, China has experienced severe ecological deterioration, such as air and water pollutions caused by its rapid urbanization and industrialization. China is now confronted with environmental pollution and ecological deterioration at a critical point, at which economic development in China is limited. Moreover, environmental problems in China have become a lit fuse for social fluctuation beyond pollution problems. The root and background of environmental problems in China, firstly, are its government's lack of understanding of these problems and incorrect economic policies affected by political and ideological prejudice. Secondly, the plundering of resources, 'the principle of development first' which didn't consider environmental sustainability is another source of environmental deterioration in China. In addition, a huge population and poverty in China have increased the difficulty in solving its environmental problems, and in fact have accelerated them. The Chinese government has established many environmental laws and institutions, increased environmental investments, and is enlarging the participation of NGOs and the general public in some limited scale to solve its environmental problems. However, it has not obtained effective results because of the lack of environmental investments owing to the government's limit of the development phase, a structural limit of law enforcement and local protectionism, and the limit of political independency in NGOs and the lack of public participation in China. It seems that China remains in the stage of 'economic development first, environmental protection second', contrary to its catch-phrase of 'the harmony between economic development and environmental protection'. China is now confronted with dual pressure both domestically and abroad because of deepening environmental problems. There are growing public's protests and demonstrations in China in response to the spread of damage owing to environmental pollution and ecological deterioration. On the other hand, international society, in particular neighboring countries, regard China as a principal cause of ecological disaster. In the face of this dual pressure, China is presently contemplating a 'recycling economy' that helps sustainable development through the structural reform of industries using too much energy and through more severe law enforcement than now. Therefore, it is desirable to promote regional cooperation more progressively and practically in the direction of building China's ability to solve environmental problems.

  • PDF

Korea's Optimal Basket Exchange Rate : Thoughts on the Proper Operation of the Market Average Rate Regime (우리나라의 적정(適正)바스켓환율(換率) : 시장평균환율제도(市場平均換率制度)의 운용기준(運用基準) 모색(模索))

  • Oum, Bong-sung
    • KDI Journal of Economic Policy
    • /
    • v.12 no.1
    • /
    • pp.111-125
    • /
    • 1990
  • For the last several years, considerable criticism has been leveled against Korea's exchange rate management. While Korea was designated a currency manipulator by the U.S., domestically it is often complained that the won/dollar rate did not adequately reflect changes in Korea's export competitiveness and fluctuations in the exchange rates of major currencies. In view of this situation, Korea changed its exchange regime at the beginning of March this year from the dual currency basket system to a more flexible one, called a "market average rate regime". Under this new regime, the won rate is determined in the exchange market based upon the supply of and demand for foreign exchange and is allowed to freely fluctuate each day within a + 0.4 % range. This paper, first, seeks to evaluate Korea's exchange rate management under the dual basket regime of the 1980s, and then to construct an optimal currency basket for the won which could provide a proper indicator for exchange market intervention under the new market average rate regime. The analysis of fluctuations in the real effective exchange rate (REER) of the won indicates that the won rates in the 1980s failed not only to offset changes in relative prices between home and trading partner countries, but also to properly respond to variations in major exchange rates as further evidenced by sizable fluctuations in the nominal effective rates of the won. In other words, the currency basket regime which was adopted in 1980 for the stabilization of the REER of the won has not been operated properly, mainly because authorities often resorted to policy considerations in determining the won's rate. In the second part of the paper, an optimal currency basket for Korea is constructed, designed to minimize the fluctuations in the REER of the won without including policy considerations as a factor. It is recognized, however, that both domestic and foreign price data are not available immediately for the calculation of the REER. For this problem, the approach suggested by Lipschitz (1980) is followed, in which optimal weights for currencies in the basket are determined based upon the past correlation between price and exchange rates. When the optimal basket is applied to Korea since the mid-80s, it is found that the REER of the won could have been much more stable than it actually was. We also argue for the use of variable weights rather than fixed ones, which would be determined by the changing relationship between exchange rates and relative prices. The optimal basket, and the optimal basket exchange rate based on that basket, could provide an important medium- or long-term reference for proper exchange market intervention under the market average rate regime, together with other factors, such as developments in the current account balance and changes in productivity.

  • PDF

A Comparative Study on Image Quality of Breast Image Tests using ACR Phantom (ACR 팬텀을 이용한 시스템별 유방검사 영상의 비교 연구)

  • Hong, Dong-Hee;Jung, Hong-Ryang;Lim, Cheong-Hwan
    • Journal of radiological science and technology
    • /
    • v.29 no.4
    • /
    • pp.241-247
    • /
    • 2006
  • Recently, interests and utilization on Computed Radiography(CR) and Digital Radiography(DR) tends to increase owing to an introduction of Picture Archiving and Communication System(PACS) and an accuracy control of special medical equipment for a breast imaging examination. This study was intended to compare and analyze a detector's imaging quality by each system to be used for the breast imaging examination by using ACR Phantom used at the accuracy control. As an evaluation method, a significance and reliability of image's value using the ACR Phantom was analyzed by using SPSS program. The results are followed. 1. For the fiber, there was 3.9 score in Screen-Film, 4.2 score in CR($50{\mu}m$), 3.2 score in CR($100{\mu}m$), and 4.2 score in DR. There was the high score in the order of CR($50{\mu}m$), DR, Screen-Film, and CR($100{\mu}m$)(P<0.05). 2. For the calcification, there was 2.7 score in Screen-Film, 2.5 score in CR($50{\mu}m$), 2.0 score in CR($100{\mu}m$), and 2.9 score in DR. There was the high score in the order of DR, Screen-Film, CR($50{\mu}m$), and CR($100{\mu}m$).(0.025(P<0.05). 3. For Mass, there was 3.8 score in Screen-Film, 3.8 score in CR($50{\mu}m$), 3.6 score in CR($100{\mu}m$), and 4.5 score in DR. There was the high score in the order of DR, CR($50{\mu}m$), Screen-Film, and CR($100{\mu}m$) (P<0.1). 4. As the total score, there was 10.4 score in Screen-Film, 10.6 score in CR($50{\mu}m$), 8.7 score in CR($100{\mu}m$), and 11.3 score in DR. There was the high score in the order of DR, $CR(50{\mu}m$), Screen-Film, and $CR(100{\mu}m$). As shown in the above results, it can be known that DR and Screen-Film System has higher image quality than CR. But, DR has unstability caused by element, and Screen-Film has the low image quality caused by artifact as disadvantages. When Dual-Side CR($50{\mu}m$) was used among CR systems which had the problem of low image quality, it was indicated that there was no difference with Screen-Film System. Because the radiation imaging examination tends to become digitalized, each system for the breast imaging examination will need to be developed and supplemented.

  • PDF

Rethinking the Records of the Japan's Korean Colonial Rule and the Post-War Compensation : Focusing on the Dual Decision Making System and the Sources of the Documents (제국의 식민지·점령지 지배와 '전후보상' 기록의 재인식 조선의 식민지지배·보상처리 결재구조와 원본출처를 중심으로)

  • Kim, Kyung-Nam
    • The Korean Journal of Archival Studies
    • /
    • no.39
    • /
    • pp.281-318
    • /
    • 2014
  • This article aims to inquire into the decision making system and the sources of the original documents made by means of it in Imperial Japan, the colonial Chosun, GHQ, and the occupied Japan in terms of the post-war treatments of compensation on the Japanese colonial rules. It deals with them from 1910 to 1952 in the perspective of history and archivistics. This article attempts to establish the foundation on which the perception of the documents made in the Imperial Japan, its colony, and the occupied territory would be widened by placing the colonial rules and the compensation on them into a continuous line. The records of Japan's forced occupation of Korea during 1910-1945, and the original records documenting the decision making process of post-war compensation under GHQ, 1945-1952, have been dispersed in Korea, Japan and the United States. This dispersed preservation was mainly due to the complicated decision-making process among Governor-General of Chosun, the Japanese Imperial government, and the GHQ. It was the top-down styled, dual decision making system, in which the critical policies, personnel, and budget had been decided in Imperial homeland, while their implementations were made in the colonies. As a result, the records documenting the whole process of domination have been preserved dispersedly in Japan and its colonies. In particular, the accounts of not yet paid Korean workers that was forced to mobilize in Japan's colonial periods, which is emerging as the diplomatic conflict between Korea and Japan, had been dealt in the decrees of the Japanese government and policy-making of GHQ. It has already been changed to the problem as 'economic cooperation' from the 'debt'. Also, the critical records for post-war compensation were preserved dispersedly in the United States and Japan under the top-down decision making process of GHQ-Japan. Therefore, the dispersed records of 1910-1952 about the colonial rules by the Imperial Japan and the post-war compensation on them must be re-investigated for the adequate documentation in the context of time and space.

The influence of fitness and type of luting agents on bonding strength of fiber-reinforced composite resin posts (섬유강화 복합레진 포스트의 결합강도에 대한 포스트 공간 적합도 및 접착 시멘트의 영향)

  • Kkot-Byeol Bae;Hye-Yoon Jung;Yun-Chan Hwang;Won-Mann Oh;In-Nam Hwang
    • Journal of Dental Rehabilitation and Applied Science
    • /
    • v.39 no.4
    • /
    • pp.187-194
    • /
    • 2023
  • Purpose: A mismatched size in the post and post space is a common problem during post-fixation. Since this discordance affects the bonding strength of the fiber-reinforced composite resin post (FRC Post), a corresponding luting agent is required. The aim of this study was to evaluate the bonding strength of the FRC post according to the fitness of the fiber post and the type of luting agent. Materials and Methods: Thirty mandibular premolar were endodontic-treated and assigned to two groups according to their prepared post space: Fitting (F) and Mismatching (M). These groups were further classified into three subgroups according to their luting agent: RelyX Unicem (ReX), Luxacore dual (Lux), and Duolink (Duo). A push-out test was performed to measure the push-out bond strengths. The fractured surfaces of each cross-section were then examined, and the fracture modes were classified. Results: In the ReX and Duo subgroups, the F group had a higher mean bond strength; however, the Lux subgroup had no significant difference between the F and M groups. In the analysis of the failure modes, the ReX subgroup had only adhesive failures between the cement and dentin. Conclusion: The result of this study showed that the bond strength of an FRC post was influenced by the type of luting agent and the mismatch between the diameter of the prepared post space and that of the post.

Distributed Throughput-Maximization Using the Up- and Downlink Duality in Wireless Networks (무선망에서의 상하향 링크 쌍대성 성질을 활용한 분산적 수율 최대화 기법)

  • Park, Jung-Min;Kim, Seong-Lyun
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.36 no.11A
    • /
    • pp.878-891
    • /
    • 2011
  • We consider the throughput-maximization problem for both the up- and downlink in a wireless network with interference channels. For this purpose, we design an iterative and distributive uplink algorithm based on Lagrangian relaxation. Using the uplink power prices and network duality, we achieve throughput-maximization in the dual downlink that has a symmetric channel and an equal power budget compared to the uplink. The network duality we prove here is a generalized version of previous research [10], [11]. Computational tests show that the performance of the up- and downlink throughput for our algorithms is close to the optimal value for the channel orthogonality factor, ${\theta}{\in}$(0.5, 1]. On the other hand, when the channels are slightly orthogonal (${\theta}{\in}$(0, 0.5]), we observe some throughput degradation in the downlink. We have extended our analysis to the real downlink that has a nonsymmetric channel and an unequal power budget compared to the uplink. It is shown that the modified duality-based approach is thoroughly applied to the real downlink. Considering the complexity of the algorithms in [6] and [18], we conclude that these results are quite encouraging in terms of both performance and practical applicability of the generalized duality theorem.

Usefulness of CT based SPECT Fusion Image in the lung Disease : Preliminary Study (폐질환의 SPECT와 CT 융합영상의 유용성: 초기연구)

  • Park, Hoon-Hee;Kim, Tae-Hyung;Shin, Ji-Yun;Lee, Tae-Soo;Lyu, Kwang-Yeul
    • Journal of radiological science and technology
    • /
    • v.35 no.1
    • /
    • pp.59-64
    • /
    • 2012
  • Recently, SPECT/CT system has been applied to many diseases, however, the application is not extensively applied at pulmonary disease. Especially, in case that, the pulmonary embolisms suspect at the CT images, SPECT is performed. For the accurate diagnosis, SPECT/CT tests are subsequently undergoing.However, without SPECT/CT, there are some limitations to apply these procedures. With SPECT/CT, although, most of the examination performed after CT. Moreover, such a test procedures generate unnecessary dual irradiation problem to the patient. In this study, we evaluated the amount of unnecessary irradiation, and the usefulness of fusion images of pulmonary disease, which independently acquired from SPECT and CT. Using NEMA PhantomTM (NU2-2001), SPECT and CT scan were performed for fusion images. From June 2011 to September 2010, 10 patients who didn't have other personal history, except lung disease were selected (male: 7, female: 3, mean age: $65.3{\pm}12.7$). In both clinical patient and phantom data, the fusion images scored higher than SPECT and CT images. The fusion images, which is combined with pulmonary vessel images from CT and functional images from SPECT, can increase the detection possibility in detecting pulmonary embolism in the resin of lung parenchyma. It is sure that performing SPECT and CT in integral SPECT/CT system were better. However, we believe this protocol can give more informative data to have more accurate diagnosis in the hospital without integral SPECT/CT system.

Low Phase Noise VCO Using Novel Harmonic Control Circuit Based on Composite Right/Left-Handed Transmission Line (혼합 우좌향 전송 선로 기반의 새로운 고조파 조절 회로를 이용한 저위상 잡음 전압 제어 발진기)

  • Choi, Jae-Won;Seo, Chul-Hun
    • Journal of the Institute of Electronics Engineers of Korea TC
    • /
    • v.47 no.1
    • /
    • pp.84-90
    • /
    • 2010
  • In this paper, a novel voltage-controlled oscillator (VCO) using the harmonic control circuit based on the composite right/left-handed (CRLH) transmission lines (TLs) is presented to reduce the phase noise without the reduction of the frequency tuning range and miniaturize the circuit size. The phase noise is reduced by the novel harmonic control circuit having the short impedances for the second- and third-harmonic components. The proposed harmonic control circuit is designed by using the CRLH TLs with the dual-band characteristic by the frequency offset and phase slope of the CRLH TLs. The high-Q resonator has been used to reduce the phase noise, but has the problem of the frequency tuning range reduction. However, the frequency tuning range of the proposed VCO has not been reduced because the phase noise has been reduced without the high-Q resonator. The miniaturization of the circuit size is achieved by using the CRLH TLs instead of the conventional right-handed (RH) TLs. The phase noise of VCO is -119.17 ~ -117.50 dBc/Hz at 100 kHz in the tuning range of 5.731 ~ 5.938 GHz.

Plasma Etching Process based on Real-time Monitoring of Radical Density and Substrate Temperature

  • Takeda, K.;Fukunaga, Y.;Tsutsumi, T.;Ishikawa, K.;Kondo, H.;Sekine, M.;Hori, M.
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2016.02a
    • /
    • pp.93-93
    • /
    • 2016
  • Large scale integrated circuits (LSIs) has been improved by the shrinkage of the circuit dimensions. The smaller chip sizes and increase in circuit density require the miniaturization of the line-width and space between metal interconnections. Therefore, an extreme precise control of the critical dimension and pattern profile is necessary to fabricate next generation nano-electronics devices. The pattern profile control of plasma etching with an accuracy of sub-nanometer must be achieved. To realize the etching process which achieves the problem, understanding of the etching mechanism and precise control of the process based on the real-time monitoring of internal plasma parameters such as etching species density, surface temperature of substrate, etc. are very important. For instance, it is known that the etched profiles of organic low dielectric (low-k) films are sensitive to the substrate temperature and density ratio of H and N atoms in the H2/N2 plasma [1]. In this study, we introduced a feedback control of actual substrate temperature and radical density ratio monitored in real time. And then the dependence of etch rates and profiles of organic films have been evaluated based on the substrate temperatures. In this study, organic low-k films were etched by a dual frequency capacitively coupled plasma employing the mixture of H2/N2 gases. A 100-MHz power was supplied to an upper electrode for plasma generation. The Si substrate was electrostatically chucked to a lower electrode biased by supplying a 2-MHz power. To investigate the effects of H and N radical on the etching profile of organic low-k films, absolute H and N atom densities were measured by vacuum ultraviolet absorption spectroscopy [2]. Moreover, using the optical fiber-type low-coherence interferometer [3], substrate temperature has been measured in real time during etching process. From the measurement results, the temperature raised rapidly just after plasma ignition and was gradually saturated. The temporal change of substrate temperature is a crucial issue to control of surface reactions of reactive species. Therefore, by the intervals of on-off of the plasma discharge, the substrate temperature was maintained within ${\pm}1.5^{\circ}C$ from the set value. As a result, the temperatures were kept within $3^{\circ}C$ during the etching process. Then, we etched organic films with line-and-space pattern using this system. The cross-sections of the organic films etched for 50 s with the substrate temperatures at $20^{\circ}C$ and $100^{\circ}C$ were observed by SEM. From the results, they were different in the sidewall profile. It suggests that the reactions on the sidewalls changed according to the substrate temperature. The precise substrate temperature control method with real-time temperature monitoring and intermittent plasma generation was suggested to contribute on realization of fine pattern etching.

  • PDF

Household Types and Changes of Work-Family Time Allocation - Adapting Fuzzy-set Ideal Type Analysis - (일-가족 시간배분에 따른 가구유형과 변화 - 퍼지셋 이상형 분석의 적용 -)

  • Kim, Jin-Wook;Choi, Young-Jun
    • Korean Journal of Social Welfare
    • /
    • v.64 no.2
    • /
    • pp.31-54
    • /
    • 2012
  • Along with increasing mothers' employment, work-family reconciliation has been recognised as a key policy agenda in contemporary welfare states. Although various policy instruments have been introduced and expanded in recent years, the problem of time allocation within couples still remains as a fundamental issue, which has been largely underresearched at a micro perspective. In this context, this study aims to identify dominant types of work-family time allocation within married couple, and to apply these types to the Korean case using the fuzzy-set ideal type analysis. Further, a series of multiple regression analyses will be implemented to find factors affecting each ideal type of work-family time allocation. The 1999 and 2009 Korea Time Use Survey datasets will be adopted for the analyses. Married couples are selected as samples only when men work 40 hours or more per week and they have at least one pre-school child. Empirical analyses cover three parts. First of all, four ideal types on work-family time allocation are classified by intersecting two core variables - the ratio of men's (paid) working and family (caring time plus domestic work) time to total working and family time. In this research, the four types will be labelled the traditional male breadwinner model (TM, high working and low family time), the dual burden model (DB, shared working but low family time), the family-friendly male breadwinner model (FM, high working but shared family time), and the adaptive partnership model (AP, shared working and shared family time). By comparing the composition of the four ideal types in 1999 and 2009, it will examine the trend of work-family time allocation in Korea. In addition, multiple regressions will be useful for investigating which characteristics contribute to the different degree of each fuzzy ideal score in the four models. Finally, policy implications and further research agenda will be discussed.

  • PDF